Temporal quantum fluctuations of the intensity of light pulses produced in the linear regime of stimulated Raman scattering are observed. A theoretical description based on the concept of coherent temporal modes is presented. The method makes use of a minimum number of random variables, which are the excitation amplitudes of the temporal modes, and allows an estimate of the probability for generating a Stokes pulse that is likely to form a soliton in the nonlinear propagation regime.

• Received 12 June 1989

DOI:https://doi.org/10.1103/PhysRevLett.63.1586